Parking Aid - System Operation and Component Description: Notes
System Operation
Parking Aid - Audible
System Diagram
Network Message Chart
PAM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Ignition key type | BCM | Used for MyKey® operation. |
| Power mode | BCM | Used to communicate the ignition switch state. |
| Transmission in reverse | PCM | Used to determine if the reverse gear is selected. |
| Trailer lamp connection status | BCM | Used to disable the parking aid when a trailer is connected to the vehicle. |
| Vehicle speed | PCM module | Used to disable the parking aid if the vehicle speed exceeds a preset threshold. |
ACM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Chime request | IPC | Used to command parking aid warning tones through the audio system speakers. |
DSP Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Chime request | IPC | Used to command parking aid warning tones through the audio system speakers. |
BCM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Parking aid active | PAM | Used to command parking aid warning tones through the audio system speakers. |
| Parking aid disable status | PAM | Used to command parking aid warning tones through the audio system speakers. |
| Parking aid range to object | PAM | Used to command parking aid warning tones through the audio system speakers. |
IPC Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Parking aid active | PAM | Used to command parking aid warning tones through the audio system speakers. |
| Parking aid disable status | PAM | Used to command parking aid warning tones through the audio system speakers. |
| Parking aid range to object | PAM | Used to command parking aid warning tones through the audio system speakers. |
Parking Aid System Operation
The PAM calculates the distance to an object within a 170 degree semicircular area (azimuth) around the front and/or rear of the vehicle. A variable rate warning tone is sounded through the corresponding audio system speakers (front or rear door speakers).
The rear parking aid system calculates the distance to an object around the rear of the vehicle using 4 ultrasonic sensors. The parking aid sensors detect objects approximately 1, 524 mm (60 in) from the rear of the vehicle, 508 mm (20 in) from the rear side of the vehicle, and 304.8 mm (12 in) above the ground. To detect objects behind the vehicle, the PAM supplies voltage and ground to the rear ultrasonic sensors while monitoring a signal return circuit from each sensor. The 4 rear sensors share common voltage and ground circuits.
This vehicle may also be equipped with a front parking aid system. The front parking aid system calculates the distance to an object around the front of the vehicle using 4 ultrasonic sensors. The parking aid sensors detect objects approximately 685.8 mm (27 in) from the front of the vehicle, 457.2 mm (18 in) from the front side of the vehicle, 304.8 mm (12 in) above the ground. To detect objects in front of the vehicle, the PAM supplies voltage and ground to the front ultrasonic sensors while monitoring a signal return circuit from each sensor. The 4 front sensors share common voltage and ground circuits.
Only objects that reflect a sufficient amount of sound waves are detected by the front or rear parking aid sensors. The surface properties, size and composition an object can affect the ability of the parking aid system to detect the object. Incorrect sensor alignment or installation, dirt or ice covered sensors, heavy rain and snow can also cause objects not to be detected.
Side Sensing
The side sensing system calculates the distance to an object around the sides of the vehicle using the four active parking aid sensors used for the active park assist. The side sensors detect objects approximately 60 cm (24 in) from the side of the vehicle. To detect objects on the sides of the vehicle, the PAM supplies voltage and ground to the front ultrasonic sensors while monitoring a signal return circuit from each sensor. The 2 front side sensors share common voltage and ground circuits with the front parking aid sensors. The 2 rear side sensors share common voltage and ground circuits with the rear parking aid sensors.
Parking Aid Audible Alert
When reverse gear is selected and an object has been detected by the front or rear parking aid sensors, the audio system volume is reduced and a variable rate warning tone is sounded through the corresponding (front or rear) audio system speakers. As the vehicle approaches the object the warning tone increases in frequency, becoming continuous when the vehicle is approximately 305 mm (12 in) from the object. If an object is detected within 305 mm (12 in) from the rear side of the vehicle that is stationary or moving away, the continuous tone is only generated for 3 seconds. If the vehicle is equipped with front and rear parking aid and objects are detected closer than 254 mm (10 in) from the front and the rear bumpers, the warning tone alternates between front and rear audio system speakers.
To generate the audio tones when an object has been detected by the front or rear parking aid system, the PAM sends the tone request message to the IPC. The IPC then performs an arbitration function to prioritize the chime and then commands the ACM to reduce the current audio volume and sound the parking aid chime through the appropriate audio system speakers.